Improvement in truss-bridges



- UNITED STATES PATENT OFFICE.

JOHN BOLES, 2D., OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN TRUSS-BRIDGES.

Specification forming part of Letters Patent No. 38,552. dated May 19,1863.

To all whom it may concern.-

Be it known that I, JOHN BOLES, 2d, a resident of Boston, in the countyof Suffolk and State of Massachusetts, have invented a new and usefulTruss for Bridges, Roofs, &c.; and I do hereby declare the same to befully described in the following specification, and represented in theaccompanying drawings, of Which- Figure 1 is a side elevation, Fig. 2 a1ongitudinal section, and Fig. 3 atransverse section, of it.

The nature of my invention consists in a combination and arrangement oftop and bottom cords, vertical tie-rods, and overlapping annuli also, ina combination and arrangement of top and bottom cords, Vertical tierods,overlapping or overlapping and interlocking annuli, and an arched beam,the whole being substantially as hereinafter described.

In the drawings, A and B are the top and bottom cords; O O O D D D, &c.,are the annuli, while E E E, &c., are the vertical tierods, and F is thearched beam. The annnli are arranged in sets of two or more of them ofdili'erent diameters, disposed concentrically. Each of these sets ofannuli, except the two end sets of the collection, are also arranged soas to lap on two other sets Where each annulus of one set crosses anyone of another set, it may interlock with it, or it may be confinedthereto by one or more nails or bolts. I prefer to make each annulus orring of what is termed angle-iron, in which case a ring would have theform shown in cross-section in Fig. 4. These rings may be notched attheir crossings, so as when put together to interlock with one another.

The truss, as represented in the drawings, exhibits two ranges of thesesets of annuli interposed between two cords, the latter being made so asto project between the ranges. The vertical tie-rods extend from theupper cord down to and through the lower one, and are confined in placeby screws and nuts arranged on their lower extremities. Between the tworanges of annuli is the arched beam F, which, at its extremities, abutson the lower cord. This beam may be bolted to one or both ranges of theannuli at points where most convenient to connect it with them.

The truss may be finished by having posts H H arranged on its ends andbetween the cords, as shown in the drawings.

A truss, when made in manner as above described, will be a verysubstantial and stiff structure, capable of enduring both lateral andlongitudinal strains with great effect and advantage.

I claim 1. The combination and arrangement of the top and bottom cords,vertical tie-rods, and overlapping or overlapping and interlockingannuli, as described.

2. The combination and arrangement of the top and bottom cords, verticaltie-rods, overlapping or overlapping and interlocking annuli, and anarched beam, the whole being substantially as described and represented.Witnesses: JOHN BOLES, 21).

R. H. EDDY, FJP. HALE, Jr.

